Synthesis, spectroscopic and computational studies of 2-(thiophen-2-yl)-2,3-dihydro-1H-perimidine: An enzymes inhibition study

Isolation, Characterization, and Single-Crystal X-ray Analysis of Lantabetulic Acid from Rhus alata: Insights into HSA and BSA Binding Interactions, with In-Silico Study

This study investigated the bioactive potential of Rhus alata, a plant known for its rich phytochemicals. A previously unreported compound was isolated from R. alata and characterized using various spectroscopic techniques (IR, UV, NMR, MS) and confirmed for the first time by X-ray crystallography. In isolated compound 1, noncovalent interactions between H···H/H···H, C···C/C···C and O···H/H···O play a major role in its packing arrangement. This observation is consistent with the results of Hirshfeld surface analysis, which quantified these interactions as 14.2%, 84.6%, and 1.2%, respectively. The isolated compound was identified as lantabetulic acid (1) (3β,25-expoxy-3α-hydroxylup-20(29)-en-28-oic acid). To understand its potential biological interactions, the binding affinity of lantabetulic acid to biomolecules such as bovine serum albumin (BSA), and human serum albumin (HSA), was assessed. The results showed significant binding efficacy, indicating potential interactions with these molecules. Furthermore, the DPPH assay demonstrated the potent antioxidant activity of this compound. We used in silico molecular docking to clarify the binding affinity between lantabetulic acid and a particular receptor. Furthermore, molecular dynamic simulation studies also explored the binding interaction. As well, MM/GBSA calculations corroborate the simulation results and the stability of the complex. Docking and dynamics studies revealed promising binding scores, suggesting further investigation into their potential therapeutic applications. Geometric parameters and the absorption spectrum of compound 1 were also determined using the DFT approach and compared with experimental findings.

Structural, harmonic force field and vibrational studies of cholinesterase inhibitor tacrine used for treatment of Alzheimer's disease

Different structures of free base (FB), two cationic forms (CA) and three hydrochloride forms (HCl) of cholinesterase inhibitor tacrine used for treatment of Alzheimer 's disease was evaluated using hybrid B3LYP calculations in order to perform their complete vibrational assignments using the scaled harmonic force fields. Structures of anhydrous form of tacrine have been optimized in gas phase and in aqueous solution. The structure of form III HCl is in agreement with the experimental determined by X-ray diffraction while the predicted IR, Raman, ¹H- ¹³C NMR and UV spectra show good correlations with the corresponding experimental ones. Energy values show that the three forms of HCl can exist in both media because these energetic values decrease from 35.15 kJ/mol in gas phase to 5.51 kJ/mol in solution. For the most stable species of tacrine, the following stability order using natural bond orbital (NBO) studies was found: form I HCl > form III HCl > form I CA > FB. CA presents the higher solvation energy value, as reported for hydrochloride species of alkaloids and antihypertensive agents. The structural parameters of form III of HCl present better concordance and corresponds to that experimental observed in the solid phase. Higher topological properties of form III together with the strong N2-H26⋯Cl31 interaction could justify the presence of this form in the solid phase and in solution and the higher stabilities in both media. The gap values support the higher reactivity of form III while FB is the less reactive species in both media. Complete vibrational assignments for FB, CA and HCl species together with the corresponding scaled force constants are reported.

Tuning the Computational Evaluation of Spectroscopic, ELF, LOL, NCI analysis and Molecular Docking of Novel Anti COVID-19 Molecule 4-Dimethylamino Pyridinium 3, 5-Dichlorosalicylate

In this work novel antiviral compound 4-(Dimethylamino) Pyridinium 3, 5-dichlorosalicylate was synthesized and characterized by UV-vis, FT-IR, FT-Raman, 1H NMR and 13C NMR spectra. Quantum chemical computations were carried out by Density functional theory methods at B3LYP level. Electronic stability of the compound arising from hyper conjugative interactions and charge delocalization is investigated using natural bond orbital analysis. Assignments of vibrational spectra have been carried out with the aid of Normal coordinate analysis following the SQMFF methodology. TD-DFT approach was applied to assign the electronic transition observed in UV visible spectrum measured experimentally. Frontier molecular orbital energy gap affirms the bioactivity of the molecule and NCI analysis gives information about inter and intra non covalent interactions. ESP recognises the nucleophilic and electrophilic regions of molecule and the chemical implication of molecule was explained using ELF, LOL. The reactive sites of the compound were studied from the Fukui function calculations and chemical descriptors define the reactivity of the molecule. Molecular docking done with SARS and MERS proteins endorses the bioactivity of molecule and drug likeness factors were calculated to comprehend the biological assets of DADS.

Synthesis, density functional theory (DFT) studies and urease inhibition activity of chiral benzimidazoles

A variety of benzimidazole by the heterocyclization of orthophenylenediamine were synthesized in 69–86% yields. The synthesized compounds 3a-f and 6a-f were characterized and further investigated as jack bean urease inhibitors. Density functional theory (DFT) studies were performed utilizing the basis set B3LYP/6-31G (d, p) to acquire perception into their structural properties. Frontier molecular orbital (FMO) analysis of all compounds 3a–f and 6a-f was computed at the same level of theory to get a notion about their chemical reactivity and stability. The mapping of the molecular electrostatic potential (MEP) over the entire stabilized molecular geometry indicated the reactive centers. They exhibited urease inhibition activity with IC50 between 22 and 99 μM. Compounds containing withdrawing groups on the benzene ring (3d, 6d) were not showing significant urease inhibition. The value obtained for 3a, 3b, 3f had shown their significant urease inhibition for both theoretical and experimental. Notably, the compound having S-configuration (3a) (22.26 ± 6.2 μM) was good as compared to its R enantiomer 3f (31.42 ± 23.3 μM). Despite this, we elaborated the computational studies of the corresponding compounds, to highlight electronic effect which include HOMO, LUMO, Molecular electrostatic potential (MEP) and molecular docking.

Recent Advances in the Synthesis of Perimidines and their Applications

Perimidines are versatile scaffolds and a fascinating class of N-heterocycles that have evolved significantly in recent years due to their immense applications in life sciences, medical sciences, and industrial chemistry. Their ability of molecular interaction with different proteins, complex formation with metals, and distinct behavior in various ranges of light makes them more appealing and challenging for future scientists. Various novel technologies have been developed for the selective synthesis of perimidines and their conjugated derivatives. These methods extend to the preparation of different bioactive and industrially applicable molecules. This review aims to present the most recent advancements in perimidine synthesis under varied conditions like MW radiation, ultrasound, and grinding using different catalysts such as ionic liquids, acid, metal, and nanocatalyst and also under green environments like catalyst and solvent-free synthesis. The applications of perimidine derivatives in drug discovery, polymer chemistry, photo sensors, dye industries, and catalytic activity in organic synthesis are discussed in this survey. This article is expected to be a systematic, authoritative, and critical review on the chemistry of perimidines that compiles most of the state-of-art innovation in this area.

Crystal structure, Hirshfeld surface analysis and DFT studies of 2-(2,3-di-hydro-1H-perimidin-2-yl)phenol

The asymmetric unit of the title compound, C17H14N2O, contains two independent mol-ecules each consisting of perimidine and phenol units. The tricyclic perimidine units contain naphthalene ring systems and non-planar C4N2 rings adopting envelope conformations with the C atoms of the NCN groups hinged by 44.11 (7) and 48.50 (6)° with respect to the best planes of the other five atoms. Intra-molecular O-H⋯N hydrogen bonds may help to consolidate the mol-ecular conformations. The two independent mol-ecules are linked through an N-H⋯O hydrogen bond. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (52.9%) and H⋯C/C⋯H (39.5%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Optoelectronic parameters of peripherally tetra-substituted copper(ii) phthalocyanines and fabrication of a photoconductive diode for various conditions

In this study, the molecular structure of 4-(4-(trifluoromethoxy)phenoxy)phthalonitrile (1) has been elucidated and its supra-molecular dynamics have been revealed by the analysis of single crystal X-ray diffraction measurements.

Structure-activity relationship of tacrine and its analogues in relation to inhibitory activity against Alzheimer's disease

Alzheimer's disease is a widespread type of neurodegenerative dementia that mainly affects the elderly. Currently, this disease can only be treated palliatively. Existing drugs can only improve patients' symptoms. The search for new drugs that can effectively treat this disease is an important field of research in medicinal chemistry. Here we report a structure-activity relationship study of tacrine and some of its analogues in relation to their inhibitory activities against Alzheimer's disease. All of the molecular descriptors were calculated at the M062X/6-311++G(d,p) level of theory. Principal component analysis of the molecular descriptors showed that the compounds could be categorized into active and inactive compounds using just two descriptors: the HOMO and LUMO energies. These results should help us to explain the activities of tacrine derivatives and to model new tacrine analogues that are active against Alzheimer's disease. Graphical abstract PCA score plot for tacrine and its analogues.

Synthesis, computational quantum chemical study, in silico ADMET and molecular docking analysis, in vitro biological evaluation of a novel sulfur heterocyclic thiophene derivative containing 1,2,3-triazole and pyridine moieties as a potential human topoisomerase IIα inhibiting anticancer agent

Computational quantum chemical study and biological evaluation of a synthesized novel sulfur heterocyclic thiophene derivative containing 1,2,3-triazole and pyridine moieties namely BTPT [2-(1-benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-6-methoxy-4-(thiophen-2-yl) pyridine] was presented in this study. The crystal structure was determined by SCXRD method. For the title compound BTPT, spectroscopic characterization like ¹H NMR, ¹³C NMR, FTIR, UV-vis were carried out theoretically by computational DFT method and compared with experimental data. Druglikeness parameters of BTPT were found through in silico pharmacological ADMET properties estimation. The molecular docking investigation was performed with human topoisomerase IIα (PDB ID:1ZXM) targeting ATP binding site. In vitro cytotoxicity activity of BTPT/doxorubicin were examined by MTT assay procedure against three human cancer cell lines A549, PC-3, MDAMB-231 with IC50 values of 0.68/0.70, 1.03/0.77 and 0.88/0.98 μM, respectively. Our title compound BTPT reveals notable cytotoxicity against breast cancer cell (MDAMB-231), moderate activity with human lung cancer cell (A-549) and less inhibition with human prostate cancer cell (PC-3) compared to familiar cancer medicine doxorubicin. From the results, BTPT could be observed as a potential candidate for novel anticancer drug development process.

Synthesis of non-peripherally tetra-substituted copper(ii) phthalocyanines: characterization, optical and surface properties, fabrication and photo-electrical properties of a photosensitive diode

This study describes the synthesis and characterization of a non-peripherally tetra-substituted copper(ii) phthalocyanine bearing 4-(trifluoromethoxy)phenol groups.

Synthesis, Antibacterial Activity and Molecular Docking of Phospholidinones in Stigmastane Series

INTRODUCTION

Steroid compounds are widely distributed in nature throughout scientific history. Living organisms such as animals and vegetables have steroids that show a significant effect on their vital activities. Sterols are key components of all eukaryotic cell membranes.

METHODS

Steroidal compounds; 3β-oxo-[1',3',2'-oxathiaphos-phalidine-2'-one] stigmast-5-ene and 3β- oxo[1`,3`,2`-dioxaphosphalidine-2`-one]-stigmast-5-ene were successfully prepared using easily accessible 3β-hydroxy stigmast-5-ene with phosphorous oxychloride (POCl3), 2- mercaptoethanol/ethylene glycol and triethylamine (Et3N) in dry diethyl ether. Products were obtained in semi-solid state and characterized using physicochemical techniques.

RESULTS

The results of the bioassay showed that the synthesized compound containing the sulfur atom had antibacterial activity. Molecular docking was also done in order to show in silico antibacterial activity and to make out the probable binding mode of compound with the amino acid residues of protein.

CONCLUSION

The results of the docking study showed that synthesized compound 2 had minimal binding energy with substantial affinity for the active site.